Plasma lipoproteins from patients with familial LCAT deficiency will be studied to explore the mechanism of transfer of cholesteryl ester to very low density lipoprotens and to characterize the physical changes in high density lipoproteins that occur following incubation with purified lecithin cholesterol acyltransferase. The effect of lecithin:cholesterol acyltransferase and high density lipoproteins on smooth muscle cells in culture also will be studied. BIBLIOGRAPHIC REFERENCE: Riddle, M.C., E.A. Smuckler, and J.A. Glomset. Cholesteryl Ester Hydrolytic Activity of Rat Liver Plasma Membrane. Biochim. Biophys. Acta. 388, 339-348 (1975).